Magnetic powered lancing drive

Abstract

A self-powered lancing drive system and lancing technique uses permanent magnets to initially store the potential energy that is converted to kinetic energy for extending a lancet during lancing. This self-powered lancing drive system is a pure permanent magnet drive that is highly reliable under numerous operating conditions. Permanent magnets can produce stronger magnetic fields at smaller sizes as compared to electromagnets. In one form, the lancing system has a drive permanent magnet that is kept fixed or stationary while the lancet magnet travels along the firing path. With the drive magnet being stationary, the lancet experiences fewer fluctuations in the magnetic field. The lancet vibrates less and is driven straighter into the tissue. In another form, a retraction magnet is positioned at the end of the firing path of the lancet, near the tissue, to enhance retraction of the lancet. In another form, a mechanical structure keeps the magnets in close proximity so that the strength of the magnetic propulsion force is maintained. The mechanical structure in one example is a crank mechanism that confines magnet movement to a circular path. The crank mechanism provides a smooth lancing profile as well as facilitates adjustments to the lancing profile.

What is claimed is: 
     
       1. An apparatus, comprising:
 a lancet for forming an incision in tissue;
 a crank being configured to rotate about an axis; 
 
 a connecting rod connecting the lancet to the crank; 
 one or more magnets configured to rotate the crank about the axis for actuating the lancet to form the incision; 
 the one or more magnets being permanent magnets; 
 the one or magnets including
 a first crank magnet attached to the crank, 
 a second crank magnet attached to the crank, and 
 a drive magnet rotatable relative to the first and second crank magnets; 
 
 a first trigger positioned to hold the crank in a first cocked position where the drive magnet is oriented to create a first repulsive force with the first magnet; and 
 a second trigger positioned to hold the crank in a second cocked position where the drive magnet is oriented to create a second repulsive force with the second magnet. 
 
     
     
       2. The apparatus of  claim 1 , further comprising:
 means for changing polarities between the drive magnet and the crank magnet. 
 
     
     
       3. The apparatus of  claim 2 , further comprising:
 a trigger positioned to hold the crank stationary as the polarities between the crank magnet and the drive magnet are changed to cock the lancet. 
 
     
     
       4. The apparatus of  claim 2 , further comprising:
 the means for changing the polarities including at least one of the crank magnet and the drive magnet being moveable to change the polarities between the crank magnet and the drive magnet. 
 
     
     
       5. The apparatus of  claim 4 , further comprising:
 the means for changing the polarities including a knob coupled to the drive magnet to rotate the drive magnet. 
 
     
     
       6. The apparatus of  claim 4 , further comprising:
 the drive magnet being configured to move in a linear fashion. 
 
     
     
       7. The apparatus of  claim 2 , further comprising:
 the second crank magnet coupled to the crank for facilitating contactless cocking of the lancet. 
 
     
     
       8. The apparatus of  claim 7 , further comprising:
 both of the crank magnets having ends with the same polarity facing the drive magnet. 
 
     
     
       9. The apparatus of  claim 1 , further comprising:
 the first trigger positioned to hold the crank in the cocked state where the first crank magnet and the drive magnet are at least in close proximity; 
 a lancet carrier to which the lancet is secured; 
 a lancet guide defining a guide channel in which the lancet carrier is disposed; and 
 the connecting rod connecting the lancet carrier to the crank. 
 
     
     
       10. The apparatus of  claim 1 , further comprising:
 a lancet carrier to which the lancet is secured; 
 a lancet guide defining a guide channel in which the lancet carrier is disposed; and 
 the connecting rod connecting the lancet carrier to the crank. 
 
     
     
       11. An apparatus, comprising:
 a lancet; 
 a first lancet magnet coupled to the lancet, the first lancet magnet being a permanent magnet, the first lancet magnet being moveable to fire the lancet; 
 a second lancet magnet; 
 a drive magnet to move the lancet magnet, the drive magnet being a permanent magnet; 
 a crank to which the first lancet magnet and the second lancet magnet are secured; 
 a connecting rod coupling the crank to the lancet; 
 means for holding the lancet magnet stationary while the polarities of the lancet magnet and the drive magnet facing one another are made the same; and 
 wherein the means for holding the lancet magnet stationary includes
 a first trigger positioned to hold the crank in a first cocked position where the drive magnet is oriented to create a first repulsive force with the first lancet magnet, and 
 a second trigger positioned to hold the crank in a second cocked position where the drive magnet is oriented to create a second repulsive force with the second lancet magnet. 
 
 
     
     
       12. The apparatus of  claim 11 , further comprising:
 the drive magnet being rotatable relative to the first lancet magnet to change the polarities. 
 
     
     
       13. The apparatus of  claim 11 , further comprising:
 the drive magnet being linearly moveable relative to the first lancet magnet to change the polarities. 
 
     
     
       14. The apparatus of  claim 11 , further comprising:
 a lancet carrier that couples the lancet to the lancet magnet.